In many types of fluid systems, and particularly in many refrigeration and air conditioning systems, the tubes (also referred to as pipes, conduits or hoses) in the system are connected together by suitable couplings, for example by quick connect couplings. In one common type of quick connect coupling, a first tube, the plug member, is inserted into a second tube, a socket member, and normally sealed by an annular seal ring (O-ring) disposed between the plug member and the socket member. The tubes are retained, with the plug member fully inserted into the associated socket member, by means of a retainer. Known retainers have included threaded connectors, segmented collets, and locking leaf-springs, collars and shells. Some of these retainers are shown, for example, in U.S. Pat. Nos. 4,332,402; 4,500,117; 5,113,900; and 5,540,463, and European Patent No. 0 031 409.
While the known quick couplers might be appropriate for certain applications, applicant believes that some of the couplers can have certain drawbacks. For example, it is believed that some of the couplers do not provide a secure, firm union between the mating tubes. This can cause excessive wear of the sealing O-ring. It is also believed that some of the known couplers lack a safety mechanism to prevent sudden separation of the mating tubes during disconnection, if pressure is present within the tubes. Further, it is believed that some known couplers are expensive to manufacture, and require numerous components or costly manufacturing steps, such as machining and brazing.
As such, it is believed that there is a demand in the industry for an improved quick connect coupler which overcomes many of the above drawbacks, and which is particularly useful for refrigeration and air conditioning systems.